Heat your oven to 350 degrees. Spray a 9x13" pan with cooking spray and set aside. Pick out the candy bars you want to use from your leftover halloween candy and chop them up till you have 2 cups, then set aside.
In a stand mixer beat the butter, peanut butter and sugars together till creamy. Add the egg, egg yolk and vanilla. Mix till creamy.
Add the flour, soda, salt & oats and stir just until combined.
Stir in the candy and chocolate chips. Press into prepared pan. Press additional candy on top if you wish.
Bake for 15 to 18 minutes or until they are lightly brown around the edge. (Don't over bake them!) Let the bars cool for 30 minutes before cutting into bars. Enjoy!
I have made these adding mini chocolate chips (in addition to the chopped up candy bars) and also with adding some chopped up butterfinger candy pieces. (You buy them by the chocolate chips!) We LOVED them with the butterfinger pieces in addition to the chopped candy. If you have a bunch of leftover butterfingers, be sure and add those in!